Date.prototype.Format = function (fmt) { 
    var o = {
        "M+": this.getMonth() + 1, 
        "d+": this.getDate(), 
        "h+": this.getHours(), 
        "m+": this.getMinutes(),
        "s+": this.getSeconds(), 
        "q+": Math.floor((this.getMonth() + 3) / 3), 
        "S": this.getMilliseconds()
    };
    if (/(y+)/.test(fmt)){
        fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "")
            .substr(4 - RegExp.$1.length));
    }
    for (var k in o){
        if (new RegExp("(" + k + ")").test(fmt)){
            fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ?
             (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
        } 
    }
    return fmt;
}